Prospective Clinical Evaluation of Intra-Articular Injection of Tin-117m ( 117m Sn) Radiosynoviorthesis Agent for Management of Naturally Occurring Elbow Osteoarthritis in Dogs: A Pilot Study.

Purpose: To evaluate the clinical effects of an intra-articular injection of ^117m Sn-colloid for management of canine grade 1 or 2 elbow osteoarthritis (OA).
Patients and Methods: This was a prospective study in 23 dogs with grade 1 or 2 elbow OA. An orthopedic examination and elbow radiographs were performed to confirm the presence of OA. Dogs were randomly assigned to receive unilateral intra-articular (IA) injection of low-dose (LD: 1.0mCi, n =8), medium-dose (MD: 1.75mCi, n =6), or high-dose (HD: 2.5mCi, n =9) of ^117m Sn-colloid. The primary outcome measure was peak vertical force (PVF) from force-plate gait analysis and secondary outcome measures included the Canine Brief Pain Inventory score (CBPI) and elbow goniometry. The CBPI was evaluated at pretreatment and then monthly post treatment for 1 year, and goniometry and PVF were evaluated at pretreatment, and at 1, 3, 6, 9 and 12 months post treatment.
Results: PVF improved at 3, and 9 months compared to pretreatment values in the HD group. CBPI scores improved at most of the time points in all dose groups. There was no significant difference in elbow goniometry between treated and untreated elbows. There were no self-reports of any adverse effects of the injection by the owners and none were noted by the examining veterinarian at the time of regularly scheduled re-evaluations.
Conclusion: ^117m Sn IA injection was free of any obvious adverse effects, improved CBPI scores, and increased weight bearing in limbs with elbow OA providing preliminary evidence that ^117m Sn may be beneficial in the management of elbow OA in dogs. Although ^17m Sn appeared to be effective for management of elbow OA in these dogs, this pilot study has inherent limitations; therefore, future studies with larger numbers and with placebo group are needed.
Competing Interests: Dr Andrews reports grants from Exubrion Therapeutics, during the conduct of the study. Dr Lattimer reports grants from Exubrion Therapeutics, during the conduct of the study. Dr Lattimer, however, had a career long interest in therapeutics of this type and has participated in privately and publicly funded work that employs radiopharmaceuticals and devices. None of this work has been done in the last several years except that associated with the parent project to this work. The study was funded by Exubrion Therapeutics, Buford, GA, USA. Drs. Aulakh, Hudson, and Fabiani are advisory board members for Exubrion Therapeutics and receive a small honorarium for consultation. All authors declare no other conflicts of interest related to this report.
(© 2021 Aulakh et al.)